1. Field of the Invention
The present invention relates to a novel branched alkyl-substituted diphenylamine and a composition containing said amine. Particularly, it relates to a novel branched alkyl-substituted diphenylamine excellent in oxidation-inhibiting property and a composition excellent in oxidation resistance containing said amine.
2. Prior Art
A mineral oil having a low aromatic content or a synthetic oil containing no aromatic ring in its structural unit, such as poly-.alpha.-olefin oil, is available as a product having high oxidation resistance by virtue of its high responsiveness to an antioxidant, though such a mineral or synthetic oil is poor in oxidation resistance in itself. However, such an oil has disadvantage of poor solvency for an antioxidant. Meanwhile, an antioxidant itself undergoes conversion when it fulfills its function and the conversion product resulting from oxidation is problematic if it forms sludge.
Japanese Patent Appln. Laid-Open Gazette No. (Sho.) 59-5146 discloses that some p,p'-dialkyldiphenylamines are useful as additives for lubricants, elastomers and so on and that the amines exhibit oxidation-inhibiting effects. However, the amines are disadvantageous in that the conversion products thereof are poor in oil solubility to form sludges.